Many electrical connectors are designed for mounting on a printed circuit board. Such board mounted connectors typically include some form of dielectric housing mounting a plurality of terminals which have contact portions for engaging the terminals of a complementary mating connector. The terminals typically have tail portions for connection, as by soldering, to appropriate circuit traces on the printed circuit board. The tail portions might be inserted into holes in the printed circuit board for solder connection to circuit traces on the board and/or in the holes, or the tail portions may be surface connected to the flat circuit traces on the board. Surface connections, such as by wave soldering techniques, are very efficient and cost effective, while inserting the terminal tail portions into holes in the board may involve complications and more costly assembly processes.
Some board mounted electrical connectors are shielded connectors to protect the electrical connections from EMI and/or RF interference or “noise”. The shielding often is provided by a metal shielding shell which substantially surrounds the dielectric housing of the connector. One of the problems with shielded connectors is that the dielectric housing often is inserted or assembled into the shielding shell from an opening which typically is at the rear of the connector. If this insertion or assembly opening is not closed by the shell, EMI and/or RF leakage occurs through the opening. Therefore, the shielding shell may be provided with a rear wall which closes the opening. Heretofore, such a rear wall had tail portions insertable into holes in the printed circuit board. Although this reduced EMI to some degree, the amount of EMI reduction has not been sufficient. Unexpectedly, it has been found that the EMI can be reduced almost as much as soldering the entire bottom portion of the rear wall to the printed circuit board by electrically connecting only a bottom portion or edge of the rear wall closest to the circuit board to a ground pad on the board by a surface connection. This shortens the electrical distance between the bottom of the rear wall and the printed circuit board and, thereby, further reduces EMI and/or RF interference.